Studies are proposed to investigate certain ecologically significant behavior patterns in mammals as they might be affected by chronic exposure to insecticides. We propose to detect and measure alterations in patterns of normal behavior (diel activity patterns, exploratory behavior, ingestive behavior, sexual behavior, agonistic behavior, maternal care) in the deer mouse (Peromyscus maniculatus), in response to chronic exposure to sublethal levels of Organochlorine insecticides. Our methodology will involve subjecting experimental groups to three dietary concentrations of organochlorine compounds ranging from 0.5 ppb to 10-20 ppb or possibly higher. Experimental groups at all treatment levels will be exposed for varying lengths of time, ranging from a few weeks to long-term tests up to two years. Their performance in behavioral tests will be compared to that of controls. After treatment and behavioral testing, the animals will be sacrificed and residue analyses and histopathological examinations conducted to establish the relationship between behavioral aberrations, insecticide level and cytological effects. Information gained from this study could provide data of predictive value in determining the effects of certain residue levels on wildlife populations and consequently subtle effects of chronic exposure in the ecosystem. The information gained can be used as a basis for studying possible insecticide influences on human behavior. By establishing the types of behavior first affected by chronic insecticide exposure, public health workers would have an indication of the types of psychological effects these compounds might induce in areas of high insecticide use.